A locomotive includes multiple different traction motors that drive separate wheel sets to propel the locomotive. Each traction motor receives electricity from a generator powered by one or more engines of the locomotive. The traction motor converts the electricity to mechanical rotation, and transfers the rotation to the corresponding wheel set via a shaft and a set of reduction gears.
The reduction gears are housed within a gear case, and the shaft passes through an opening in a first side wall of the gear case. A pinion gear is connected to an end of the shaft opposite the motor and engages a bull gear inside the gear case. The bull gear is connected to a corresponding wheel shaft, which extends through an opening in an opposing second side of the gear case. Seals are located around the motor shaft and the wheel shaft at the first and second side walls to help retain lubricating fluids within the gear case. The seal around the motor shaft is commonly known as a pinion seal.
Historically, the pinion seal has been fabricated from an adhesive. In particular, an adhesive was applied to the gear case and to surfaces of the traction motor and allowed to set, so as to create a fluid tight seal around the motor shaft. This type of seal, however, often does not bond properly with the gear case and/or the traction motor due to residual oil or debris left on the surfaces from machining processes. In order to try to improve bonding of the adhesive, strict cleaning regimes have been implemented. The adhesive seal has still proven to fail under certain conditions, allowing lubricant to leak from the gear case, and the strict cleaning regimes have increased a cost of seal fabrication.
An alternative pinion seal is described in U.S. Pat. No. 5,123,297 that issued to Renk et al. on Jun. 23, 1992 (“the '297 patent”). Specifically, the '297 patent discloses a lubricant retaining device molded from a deformable elastomeric material. The device has a base, a rim with compressible lips, a column connecting the rim to the base, and deformable legs extending from the base. The rim is configured to receive a traction motor collar, with the lips extending radially inward into a groove of the collar. The legs of the base are configured to extend in an opposite direction (i.e., radially outward) into a holding channel of an associated gear case. When installed, the lips and the legs provide a slight interfering fit within the groove and the channel, thereby creating a seal that inhibits leakage of lubricant from the gear case.
While the lubricant retaining device disclosed in the '297 patent may have improved sealing over the traditional adhesive discussed above, it may still be problematic. In particular, the device, because of the need for precise placement of the lips and legs within corresponding grooves and channels, may be prone to improper assembly and/or damage during assembly. In addition, because the device relies on a single means of sealing (i.e., an interference fit), the device may have reduced applicability (e.g., applicability to only low-pressure applications and/or highly viscous applications).
The pinion seal of the present disclosure is directed at solving one or more of the problems sot forth above and/or other problems in the art.